Objective To understand the growth of three Eucalyptus species of the genus Corymbia introduced in Guangxi, and preliminarily select species, provenances and families with disease resistance for providing scientific basis for the orient cultivation of sawn wood.

Method Based on the 3 month-old provenance/family trail of Corymbia in Guangxi State Sanmenjiang Forest Farm, tree height and disease status were investigated. The disease resistance index was used to analyze the disease status., Differences between species, provenances, and families were evaluated by analysis of variance. Genetic variation parameters of traits were estimated, and the excellent species, provenances, and families for disease resistance were selected by independent elimination method.

ResultsThe results showed that: tree height, survival rate and resistance disease index had significant difference among four species (P < 0.001); there were no significant difference in height, survival rate and resistance disease index between provenances of Corymbia maculate and Corymbia henryi. The three traits were significant different among the families of these two provenances (P < 0.01), except that the disease resistance index of Corymbia maculate was not significantly different among families; there were extremely significant differences in tree height and disease resistance among the provenances and families of Corymbia citriodora ssp. variegate (P < 0.001), but the differences in survival rate were not significant; the difference of resistance disease index among provenances and families of Corymbia citriodora were significant (P < 0.001), but difference in height and survival rate were not significant. The heritability and repeatability ranged from 0.05 to 0.43, which was controlled by weak to moderate genetic intensity. Corymbia citriodora was the superior species with the best growth and disease resistance. A total of 7 provenances and 47 families were selected. Their mean values of height, survival rate and resistance disease index were 57.1%、1.8%、67.4% and 57.1%、0.9%、69.8% higher than the population mean values, respectively. The genetic gains of height and resistance disease index of provenance and family were 12.0%, 21.9% and 17.1%, 21.6%, respectively.

Conclusion The disease-resistant species, provenances and families were selected, which provides basis of germplasm materials for further breeding.